It is interesting how a combination of ideology, tax breaks and the possibility of blackouts have been driving more and more people to add solar roofs to their homes in several parts of the USA. Businessweek has a nice article that explores the costs involved and the other related issues that would affect the cost specifically at: http://www.businessweek.com/magazine/content/08_44/b4106088155598.htm?chan=autos_real+estate+--+lifestyle+subindex+page_real+estate+news
As far as South Asia is concerned, the issues would be completely different, though. Severe power shortages would make solar roofs more a matter of getting power reliably without having to depend upon the miserable government utilities than an issue of ideology or whatever. That they would reduce the amount of electricity consumed from filthy coal fired powerplants would be a huge plus, though. I wish some Indian business newspaper or magazine would do something about this in an Indian context. I am sure there would be more than a little interest. My guess is that thiswill happen - I do hear from people who want this kind of information and, soon, some savvy Indian publisher / editor is going to realise that this demand exists and start offering news to satisfy his readership.